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RE: Ceratosauria vs. Neotheropoda?

Aside from what Mike Taylor said, it should be noted that as it stands, the 
concensus on definitional restrictions is to be as inclusive as possible with 
reference to original intent without limiting your options. If we want the name 
Ceratosauria to contain only a paraphyletic or polyphyletic grade with respect 
to tetanurans or "neotetanurans," then we can make it a self-destructive name 
(it would only be true if the given arrangement of taxa were accurate in a 
given phylogeny). Otherwise, we can throw that out and define Ceratosauria 
thus: "The most inclusive clade containing *Ceratosaurus nasicornis* but not 
*Passer domesticus*." (Or whichever bird one might want to use; I've not been 
particularly fond of *Vultur gryphus,* nor do I think it's a particularly 
exemplary species of bird [perhaps *Columba livia* instead?].)


Jaime A. Headden

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> Date: Fri, 20 Nov 2009 19:59:17 -0300
> From: augustoharo@gmail.com
> To: dinosaur@usc.edu
> Subject: Ceratosauria vs. Neotheropoda?
> Question for people who know about Phylocode:
> Langer et al. (2009) pointed out that the oldest available
> phylogenetic definition of Ceratosauria is synonymous with
> Neotheropoda. They point out that Rowe and Gauthier (1990) defined
> Ceratosauria as a node-based taxon this way: "We employ the name
> Ceratosauria for the group including Ceratosaurus nasicornis,
> Dilophosaurus wetherilli, Liliensternus liliensterni, Coelophysis
> bauri, Syntarsus rhodesiensis, Syntarsus kayentakatae, Segisaurus
> halli, Sarcosaurus woodi , and all other taxa stemming from their most
> recent common ancestor".
> Sereno (1998) defined Neotheropoda this way: "Coelophysis, Neornithes,
> their most recent common ancestor and all descendants", and later
> (2005), this way: "The least inclusive clade containing Coelophysis
> bauri (Cope 1889) and Passer domesticus (Linnaeus 1758)."
> Accepting the phylogenetic hypothesis of Rauhut (2003), that what
> Gauthier called Ceratosauria is not monophyletic, with Ceratosaurus
> being closer to Tetanurae than to Coelophysis, it seems that both
> definitions group the same taxa, as expressed in Langer et al (2009).
> Is there a reason for not using Ceratosauria instead of Neotheropoda?
> The definition by Rowe and Gauthier (1990) seems like acceptably
> constructed from the comments.
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